Question: What do Dexter, True Blood and The IT Crowd have in common? Before you start wondering about serial killers, vampires and computer geeks, rewind a bit. Answer: They are all TV shows with brilliant opening-title sequences.

A good title sequence is like the bartender from one of those old black-and-white movies who looks up with a warm smile when you walk in. ‘Hey buddy,’ he says, ‘nice to see ya again, same as usual?’ It isn’t something you fast-forward through to get to the beginning of the show; it is the beginning (annoying pre-credits sequence notwithstanding). More than that, at its very best a good title sequence can be like a great cinematic close-up-part of the whole, but self-contained and transcendent.

Two people that understand this idea more than most are Nic Benns and Miki Kato, the creative forces behind Momoco, the company that designed the titles for TV shows like BBC’s Luther and ITV’s Father & Son, as well as many films including An Education, Hard Candy and 40 Days of Night.

“We treat it like a book cover for the show itself,” reveals Benns. “It’s lovely if it’s like a little film in its own right, but it must always live in the same space as the show. It’s got to really set the mood and tone and draw the audience in so they know where they are.”

Indeed, that’s what a good title sequence does. Watch the True Blood credits and you instantly know where you are: it’s a Louisiana swamp, it’s hot and you’re starting to feel that V you took earlier kick in. Even something like Lost with its cursory opening puts you in the right place, like a swish of the Smoke Monster’s tail snapping you onto the island.

In order to reach this level of symbiosis, Benns and Kato explain that title designers require as much information as possible about the show. This usually means seeing a rough cut, but sometimes, Benns goes on to say, this is not always the case.

“At the moment we’re working on a major new sci-fi for the BBC. They’ve just begun shooting but they’ve got us involved very early because they want something really special. All our concepts are coming from the script and we’re not sure how far we’re able to push it. We don’t want the technological aspect to be beyond what they’re visualising in their show.”

Naturally, this implies that some of their ideas might well end up spilling out into the show itself. Kato agrees. “I think that’s what the director wants. He wants to have input from us as well for the film.”

“Yeah,” Benns adds, “and then he’ll probably rein it back later on. It’s quite exciting to see what they come up with and then see if our worlds meet.”

The Momoco office, situated in London’s Carnaby Street, is kind of small and poky – bijou let’s say – but it feels like a place of big ideas. There’s a sense of fun in the air. On Benn’s desk, perched incongruously next to an expensive-looking Apple screen, is a pink 70s-style telephone; casually propped up against the wall underneath a row of stacked hard drives, is a piece of artwork specially commissioned from comic-book artist John Burns.

And they’re visibly excited to have a visitor. Benns brings out the storyboard pitches that they created for Luther. Nobody really gets to see them, he explains, and as he flips through the boards, explaining the concepts behind each one, you can see the pleasure and pride in his face.

“This one is like tiles shifting and then coming together, like solving a case… this one represents the duality of the character, so we’ve got this mirroring going on… this one was a bit off because he wasn’t really a forensics expert… this one’s probably too gory for them… this I think was probably too pretentious… that’s like the hunter and the hunted…”

So much effort and detail has gone into each storyboard that it seems such a shame they’re hidden away and not hanging in some trendy art gallery somewhere. Benns explains how they spend a whole day simply coming up with logo ideas.

“Typeface has got to be a character through the narrative. It should really carry a part of the story. For Luther we had shards, these fragments of type coming together, like he’s piecing a case together.”

The two designers met at the California Institute of the Arts and decided to bring their love for typography and motion graphics to London. But, as Kato points out, there are still big differences between America and the UK.

“Film titles in Britain are a kind of afterthought,” she says. “It’s not something you budget for at the very beginning for the making of the entire show. When they start thinking about the titles, not much budget is left. Whenever they approach us, it’s ‘Sorry, we don’t have the budget, but can you do that?’”

“That’s where the balance comes,” Benns continues, “because we can push things, be a bit more experimental. We tend to do more creative work with tight budgets because we’ve got that freedom.”

Watching a series of title sequences from the latest ‘hot’ shows, one begins to get a sense of cross-pollination going on. Is there a body of work emerging that we’ll look back on one day and say that was this phase or that phase? Luther certainly feels American, even though it’s difficult to pinpoint why.

“If it’s a TV show,” Benns says, “our clients love True Blood or Dexter, and it’s usually American shows that they’d like us to reference. If it’s a comedy, Desperate Housewives, and if it’s a film,Se7en is constantly brought up.”

“We would try to have the same mood,” Kato quickly adds, “but not style. We don’t want to copy other people’s work.”

Another critical element to a successful sequence is its music. When that Alabama 3 track ‘Woke Up This Morning’ kick-starts The Sopranos, who hasn’t angled their foot slightly, pressing down on the imaginary gas pedal, secretly imagining they’re Tony Soprano cruising down the New Jersey Turnpike getting ready to bust some balls?

“At the pitching stage we don’t usually know the music,” Kato says, “which is good because that frees us up in terms of pace.”

Continues Benns, “For Luther they gave us the whole song. We did one edit with the instrumental part of the song, which was quite moving and timeless. But they really wanted the soulful voice so we took part of the chorus and then a bit from somewhere else. It’s a quite truncated version but it works very well.”

There are rules, of course. Rules that, as Benns says, cannot be broken on any old creative whim. “With TV they often ask us to feature the main actor because they want to really sell the point that they’ve got a star in the show. I feel that’s a bit of a compromise, but we try different ways of subtly introducing the character. Every name has got a legal size attached to it. So many years ago, a colleague of mine worked on a film with Arnold Schwarzenegger, and his name had to be 200 per cent the size of the title. That’s an extreme case. Every agent’s got a negotiation of the order and size of each credit and that can take a while with them sorting themselves out. Even though certain names are the same size, sometimes the background might be more sparse or minimalist and then that makes them more prominent, so then the producer or the agent will ring up and we end up having to compromise and even things out. It can sometimes really ruin the pace and dynamics of a sequence.”

Looking through Momoco’s catalogue you start to get a sense of their style. There’s certainly a comic-book sensibility slipping through, which Benns is quick to confess comes from him. There’s also a textural, intricate, layered quality to their work, evident not least in their BAFTA-nominated sequence for the teenage show Misfits.

Kato is more casual about her own artistic influences. “Mainly,” she says, “mine come from daily life, just living as a normal person. Like the audience. Because if I’m different, I can’t empathise. I want to know their tastes and what they like. I’m just like them, very normal. Also, everything has something beautiful if you look at it from different angles. Beauty is always there.”